Many long-term wheelchair users suffer from chronic shoulder pain. This problem is significantly caused by the loads acting upon the upper extremity and trunk during the wheelchair propulsion. This project involves the mathematical development and determination of the upper extremity joint forces and moments during wheelchair propulsion. The upper extremity and the trunk are modeled by a 3-D four-bar link system representing trunk, arm, forearm, and hand and with 10 degrees of freedom. Included in the model also are the significant muscle forces. Knowing the hand-rim interface loads and geometric factors of the wheelchair, the optimal wheelchair/user match may be obtained.

Bones in normal condition are electropositive. When one is broken, there are electronegative charges around the broken part which enhances the healing process. Although there are some invasive approaches to maintain this electronegativity, noninvasive electromagnetic stimulators are preferred. This project involves the development of a biomechanical model of the bone-healing process. The model will be used to obtain the optimal design parameters, such as wave form, intensity, and geometric parameters, for the most efficient bone-healing process. Two new strategies, discontinuous stimulation and time-dependent stimulation, will be considered. A laboratory prototype stimulator using optimal parameters will be designed and manufactured.

Walking is the basic means of locomotion for human beings. Various aspects of walking have been studied by a number of researchers; however, there is limited information on the unique characteristics of changing direction during walking. This study investigates the kinetic walking patterns and properties of the ground reaction forces (GRF) in changing direction. Thirty-three subjects are tested through a walking protocol representative of all of the complex movements of directional walking. Their GRF and body movements are recorded via a force plate and motion analysis systems, respectively. The insight gained in this study will be helpful in the clinical diagnosis of dysfunctional walking.

The purpose of this research is to examine the propagation of impacts through the lower leg. The bone joint-system of the leg is modeled, taking into consideration the nonlinear, viscoelastic nature of a typical knee joint and the material nonlinearities inherent in the bone structure. The model is analytically and numerically studied to determine how impact forces travel through the lower extremity. Such impacts, with peek amplitudes ranging from three to five times the body weight, are normally generated during the landing phase of jogging, running, and jumping. An isolation shoe mechanism is then conceived to attenuate and scatter the detrimental components of the input shock. The results are verified through experimental force plate measurements.

The purpose of this research is to investigate the sequential motion and interaction of the upper extremity in underarm throw through the study of the relationship between kinematic factors and muscle activities. The proximal-to-distal sequential motion (a whip lash-like action) of the upper extremity is frequently associated not only with fast movements, such as throwing and kicking, but also with slow movements, such as running and walking. Kinematic data of several subjects are collected via high-speed cameras and digitizing systems and selected muscle activites are recorded by surface-mounted electrodes. The results of this study will enhance understanding of the muscle usage, joint forces, and torque and provide the biomechanical basis for the prevention and prediction of injuries in various sport activities.

The project goal is to determine why some wheelchair users experience shoulder pain while others do not. Due to the anthropometric differences in wheelchair users and the geometric variables of the available wheelchairs, it is hypothesized that some users will develop unnecessarily high forces in their shoulder joints during wheelchair propulsion. A standard wheelchair wheel is being modified and instrumented to provide telemetric data describing the magnitude and direction of all forces applied to the hand rim. This force data will be combined with video digitization data of the 3-D motions of the arm, forearm, and hand during wheelchair propulsion.

In order to determine the physiologic effects of manual wheelchair propulsion technique, user/chair geometry, and environment, an understanding of the loads and stresses within the joints of the arm is needed. The reaction loads of the hand on the wheel handrim is determined by using an instrumented wheel. These loads, along with kinematic parameters, are being used with structural dynamics software to examine the loads within the joints. The goal is to reduce the shoulder pain attributed to manual wheelchair propulsion.

Although most people with physical or sensory disabilities have normal or above normal intellect, they are severely underrepresented in the technical fields, both at the college level and in these careers. The goal of this research is to identify the obstacles that may be contributing to this problem, whether they be physical or attitudinal, and develop methodologies to eliminate them.